Predictors of major adverse cardiovascular events: first report from the Australian-New Zealand Spontaneous Coronary Artery Dissection (ANZ-SCAD) Registry

Introduction Spontaneous coronary artery dissection is an increasingly recognised cause of acute coronary syndrome (ACS). There are limited data assessing independent predictors of major adverse cardiovascular events (MACE) following SCAD. Aim To describe the clinical characteristics of people with SCAD and to determine predictors of MACE and SCAD recurrence. Method Multicentre, prospective and retrospective cohort study involving 23 Australian and New Zealand sites. Patients >=18 years with an ACS secondary to SCAD confirmed on core laboratory adjudication were included. Multivariate Cox proportional hazard models were used. Results From 507 patients, n=440 (137 prospective, 303 retrospective) had confirmed SCAD; mean age 52.4±10.7 years, 89.8% female. MACE and SCAD recurrence occurred in 8.3% and 3.2%, respectively at median 15-month follow-up. Risk factors for MACE included anticoagulation use on discharge [adjusted hazard ratio (aHR) 4.8, 95% confidence interval (CI) 1-11.8, p=<0.001], history of AF (aHR 7.6, 95%CI 1.7–32.9, p=0.007) and the presence of fibromuscular dysplasia [(FMD), aHR 2.7, 95%CI 1.2–6.2, p=0.02). Anticoagulation (aHR 7.3, 95% 2.4–22.3, p<0.01), FMD (aHR 5.2, 95% CI 1.8–14.9, p=0.002), history of stroke (aHR 5.5, 95%CI 1.2–24.2, p=0.02), and dual antiplatelet treatment with aspirin and ticagrelor (aHR 2.2, 95% CI 1.1–4.6, p=0.03), but not aspirin and clopidogrel, were associated with SCAD recurrence. Conclusion The risk of MACE was five-fold higher in patients on anticoagulation and three-fold higher in patients with FMD. SCAD recurrence comprised a large proportion of overall MACE. Dual-antiplatelet therapy combining ticagrelor and aspirin was associated with a higher risk of SCAD recurrence.